kropp



MOP?.

l MR PRQPgLLEH. AND THE LiKE.

.APPLICATION FHLEU JULYS, l914.

Patented Aug. 8, 1916.

Aiforney Saxony an c mman en lili@ `a Re..

EAR DRESDEIE',

To 1U/Ulmen t may Concern:

lie it known that i, Ginn Knorrj a citizen of the German Empire, ondresident oi Deuben, neer Dresden, in the Kingdom of l German Empire,have invent-` ed certain new :uid useful improvements in Air-Propellersand the like olf which the ii'oilowing is e speciication.

My invention relates to a device applicrible to the propulsion oiceroplencs, and

particiihn-lj7 to i device ofthe type in which lifting surfaces wrongedwithin e drinn are alternately `centreeted or folded and expanded orspread ont. .As constructed hitherto, sich devices eiiect thecontraction of the iiiting surfaces after their working stroke, eitherby lneans of springs connected with rollers carrying one eiid of therespective surfacesj or by ineens of a, special opera-ting deviceconnected ii'ith the rollers carrying the one end of therespective-enrfe'ces and serving to wind up these surfaces after theirWorking; stroke. Each of these old constructions is deficient in that.it fails to insure the reliable operation which is re- 3o the springs,in 'the other construction a sepeelement and quired i111 the cese oit anaeroplane; in the one construction, the :proper operation of thedevicedepends on the goed quality and condition and. on the proper strength ofrate complicated actuating device is necesor each driving elementconsisting of a-'drun1, Wi ich in devices of the present is always usedin conjunction with another is provided-in e plurality of elementsv Thedevice inventedby nie eiiords an alosolutely reliable operation, thecontraction and expnsion of the lifting members or sur- 40 facesoccurring automatically es the drum rotates, Without any sfiecinladditional mechanism for eiii'ecting such expansion and contraction. Forthis purpose, the lifting' niembers are located between theperig'iherics of two drums one of which is located within A speed.

the other, and the desired operation is ohtained simply by rotntingr'these drums on. their respective axes, :it the suine rate of' The innerdrum is arranged eecenti'i 5'0 cally Within the outer drums and thiltgior tion of the periphery or the innerfdrnm whichv moves downward(hiring the opere.- i tion, extends to or beyond the exis of tie outerdrum ln the accompanying drawings have shown the application of myinvention for Specification of Le .t rs Patent.

row

. vspokes IAL lo,

`zllel 'to the'other :ixles hubs 112, 13,

i i. Serial H0. sfh'.

its 'preferred purpceey 'vir/1 n, lifting' action, iigiure i h ng :iside cierre tion of ze. driving element, if 2 n horimntnl Sectionthrough the center ci? Fig. i; Fig. e, diagrammatic rcnr elevation of:in neroplzine (of the flying hoot type) in ided with two drivi that ofexerting invention, this view heine' ou t Snnillersczzle than Figs. land und Fig. #i is e detail. YView (upon :i larger ecole) showing thedriving mechanism of the conetriiction represented in if`ig. $3, es seentroni above.

iiilithin the drinn l, consisting ci two rim 2, 3,huhs i? 5, spokes 6, 7conm-:cting th' hubs-with the respective rinie: and rods connectingoneriri with the othifri tiiere arranged zt eiiizfeiicr drinn 9,c"f\'sistiiig in iilie nienner of rime l0., 1L hubs, l l 13, l and iongnidinul roos or braces 1G, The nitro o. rods S is equal to the number orrods i6; the seid rods :irc arranged in. vpatire erich coi'njjirisii sirod 8 :rnd n rod 1G, and the two rods of each pair are connected by :tliifting ineinber 17 made suitable Flexible or' textile 'fabric or othn'nxterini. The hnhs i, ere jonrnzried upon' dining :rides 19, Securedto 'the freine i8, and seid axles :ire connecterl 'hy horizontal stays2i, 22 respectively with nn aude para and supporting the'irziinsinissioii chains 24:. 25 cc1ineet the hubs #i rind 5 with thelinie :ind 13 res' eci\fei \j, the siirrock, engaged by seid chainsheg/ing the seine ninnher ci teethg so that the two drinne will li.

in@ elements according to my GII tary speed or angular Yeioc' y. alsocarries :mother sprocket 26 engngcd b v :i driving" chain Q?. To theiiin'cr ends of the hubs l2, 3 of the drinn i) fare secured propeilingscrews or propeliers 2S, 2) respectively oi opposite Ditch :ind soconstructed :is to force nir inwzirrrlly when the drinne :irc rotating;:me to dfliver such nir to the lifting' members l?.

iillien the' flrnins L 9 :ire rotated by the chain 27', sprocket 2o? andchnins 2i, 25, noch oi1 the iiiitinje; 'e doers 17, coixsidercd :is :Leheh:7 :swings :dicht :in :Ulis which lies :it the intersection of 'thehor' html contini pinne ot' the device :nid ot tl." :chine ccnhriiiihgrthe tvc rods S, "ifi of tl'mt'iizii members 17 secured thereto, whichare inst in line with the corresponding inner rods 16 in the .centralposition shown at the extreme left in Fig.' l, will, on account of theirgreater linear speed, gain on or travel ahead of, the correspondinginner rods 1G which carry the inner ends of the respective lift# ingmembers 17 This lead oftheouter end oi the lifting members iS quiteconsiderable even shortly after the lifting member has risen romthecentral position shown at the extreme left in Fig. l, which is the fullyfolded or contracted position. The result is that even shortly afterpassing this point the members 17 tend to exert a lifting action,forming as it were pockets to catch the air and carry it around.H Thelifting sur- 'faces or members 17 therefore will exert no ,liftingaction only at a small portion oil' the device, say about the portionwhich lies to the left of a vertical plane passing through lthe axis D.

Placing the axis of movement oit the littn ing members at one eine, asat l), (instead of centrally)Y presents another important' advantage.That is to say, the linear speed ofthe inner edges (rods le) of fthelifting members 17 at the points where the greatest eliiciency isobtained (extreme right in Fig. l), is materially greater (owing to thegreater distance or radius) than if the said axis were for instancecoincident with the aXis of the drum l. The result is that the center ofpressure of 'the air-,resistance is brought as far as possible Alioiiithe `center of the lifting members, and thus i obtain a very eiiicieiitlifting action of said members.

The screws or propellers 28, 29 may be ar ranged outside of the twodrums l, 9 instead of inside as shown. Provision may also be' made forstopping one or the other ot these screws, so that thec one screwremaining in operation will have the function, not only of Yforcing airinto-the drums l, 9, as explained above, but also of propeliing the body(aeroplane) which carries the device.

In Fig. 3 l have shown the general ar rangement of an aeroplane (flyingboat) 4provided with my improved driving or prop'elling device. .Theframe 18 is secured to the .boat hull 3l provided with landing Wheels3() and carrying at each. side one or more pairs of driving elements l,9. Within the hull 3,1 is arranged the main shaft 32, operated say by aninternal combustion motor vand transmitting its motion by mea-ns of achain 33 to a. sprocket Wheel 54 and to its shaft 35. The latteractuates adifferential gearingBG; this on one side operates a spur-Wheel 37 .mounted loosely on the shaft 35 and meshing-With gear 38 onthe shaft of which is also secured a sprocket 39 operating the cha-in27, while on the other side of the differential gearing there is asprocket 420 likewisel loose on the shaft'. 'On' the tively. The shaft35 further carries the main .propeller 45 of the aeroplane or flyingboat.

Vith the arrangement shown in Figs. 3 and 4, if a current oif air shouldstrike only one of the pairs of driving elements l, Q and impede orretard the operation oit this pair, an equalization is obtainedimmediately by 'the automatic action of the did'erential gearing Whichin this case will cause the corresponding pair oi elements l, 9 on theother side or' the aeroplane to be accelerated oi' speeded up. Thisaction, to `Wit, the-acceleration of one pair of lifting or drivingelements relatively to the other pair driven by the same differential,may be obtained at any time at the operators Will, by applying one ofthe brakes i3 or dei. The transverse oi' lateral stability et" theaeroplane is there fore ver f O'reat both. as to automatic cone devicewill.. operate as a Various modifications may be inade with# outdeparting from the nature oit my invention as set forth in the appendedclaims.

l claim as my invention:

l. A. device ci' the class described, comprising two drums of diilerentdiameters, one located Within the other eccentrically, aconnectionbetween said drains whereby they are compelled to rotate in unison, andilexible connecting members or surfaces entending from one drum to theother and adapted to be expanded and contracted alternately as i thedrums rotate.

2. A. device oi' the class described, com prising two drums ot'different diameters, 'one located Within the other eccentricaily andreaching .at least to the center of the larger drum, a connectionbetween said drums whereby they are compelled to rotate in unison, and*flexible connecting mem-' bers or surfaces extending from one drinn tothe other and adapted to be expanded and contracted alternately as thedrums rotate.

3. A, devicel of Jche class described, comprising two rotary members,one located Aeccentrically Within the other, a connection between saidmembers 'whereby they are compelled to rotate in unison, and ileXioleconnecting members or surfaces extending from lli) ine/noe? one rotarymember to the other and adapted to be expanded and contractedalternately as said members'rotate.

4. A device of the class described, comprising two rotary members, onelocated ec centrcally Within the other, a connection between saidmembers -Wliereby they are compelled to rotate-in unison at'the sameangular velocity, and iiexible connecting membersfor surfaces extendingfrom one rotary member to the other -and adapted to be eX- l anoperative connection' between tbe two drums to compel them to rotate inunison, and exible members or surfaces having their respective endssecured to corresponding longitudinal rods of the two drums.

6. A device ot the class described, provided with members arranged torotate about parallel axes, connecting members of iexible materialextending from one rotary member to the other and adapted to be expanded4and contracted alternately as said members rotate, and means fordirecting a fluid toward said connecting members.

ln testimony whereof, l have signed this specification in the presenceof two subscribing Witnesses. l u

' y CARL KROPP. Witnesses:

L. A. BnRGHoLz, PAUL Anims.

